Onyxia is immune to all abilities which cause a monster to instantly target the caster. So, abilities such as Taunt, Challenging Shout, and Mocking Blow don't work as usual on her. Other threat-generating abilities such as Sunder Armordo work as usual.

Fire Immunity

Onyxia is immune to all fire spells and effects.

Whelp Eggs

At the East and West sides of Onyxia's Lair are the two entrances to a tunnel full of eggs. When a character gets too close to the eggs, many whelps will hatch and attack.

Warder Respawn

As soon as Onyxia is engaged, her Onyxian Warders respawn in the tunnel. They despawn as soon as she is defeated. These Warders discourage players from hiding from her in the tunnel.

Teleport

As with many other raid bosses, Onyxia will teleport characters to herself if they are far away or unreachable when she is in combat. This usually happens to characters in the entrance tunnel, but can randomly happen to characters at any position in her lair.

This is a blast of fire that hits everyone in front of Onyxia, including to a considerable distance to the sides. This damage is fire based and hits for upwards of 4000 damage. At level 70 it is very easy to survive a Flame Breath.

Onyxia can attack everyone behind her with her mighty tail. This hits for very little damage (about 300) but sends the target flying sideways. This attack can cause a wipe if the victim gets knocked into a whelp cave.

While in flight Onyxia will breathe fireballs down on random players. This hits as a main hit and a splash damage hit. It does up to 3000 damage to the player it hits and can do up to 1500 to anyone nearby. Note: Research in November of 2006 strongly indicates that these fireballs target whoever is highest on Onyxia's threat list, and impose a large (probably complete) threat wipe for the characters targeted.

Whelp Spawns

Groups of whelps periodically hatch from the eggs and attack, regardless of whether any characters are near them. This includes a large spawn at the start of the phase, and small spawns periodically during the phase.

Onyxia emotes "Onyxia takes in a deep breath..." and a few seconds later, she flies across her chamber as she breathes a huge gout of fire that rolls straight across the room from her initial position to the opposite wall. Characters in the middle of this attack get hit five or six times and are likely to die. Characters on the sides of the attack get missed entirely or get hit only once.

Despite being "breaths" they don't actually originate from the front of her — they actually originate from the floor directly beneath her and travel directly to the opposite corner or side of her lair. Melee who attempt to stand under her to DPS should keep this in mind and be prepared to immediately run to a safe spot if a deep breath occurs.

There were many theories about deep breaths being caused by clumping, not enough DPS, or the number of debuffs on her, however Jeff Kaplan stated in a video interview with the developers in June of 2007 that the trigger for the Deep Breath is "totally random" [1].

It is human nature to find patterns in randomness, so many players insist that they know exactly what causes the deep breath attack. However, each of these theories has been tested and found to be false. There are only two techniques that have been proven to work against Deep Breath attacks: Damage her more quickly so that she has fewer opportunities to perform the attack, and move out of the way when she does perform it. See below to see how to dodge this attack.

Note that well-geared guilds can bring her through Phase Two so quickly that she only moves a couple times, and thus has a good chance of not performing the attack at all. The members of these guilds report that their techniques work because Onyxia hardly ever uses her Deep Breath attacks any more. In fact, the time spent perfecting their techniques was also time spent gathering powerful gear, so Onyxia is simply not in the air long enough to perform the attack. Anyone wishing to promote a theory about what causes the attack should test it by leaving Onyxia up in the air for at least 15 minutes, which will be long enough to collect useful information.

Onyxia does an AoE fear at random intervals, causing everyone to run around randomly for a few seconds. Sometimes there are 30 seconds between fears and sometimes as little as 10 seconds. Just before she casts the fear, the screen shakes. After the fear is over, the lava cracks spew forth lava for a few seconds. Characters hit with the lava take about 1,500 points of fire damage (unresisted).

Whelp Spawns

Small groups of whelps occasionally spawn from the eggs and attack, regardless of whether any characters are near them. These spawns are rare, unlike the common spawns in Phase Two. These spawns are comprised of five or so whelps, unlike the huge spawns of 20+ whelps that result when characters are feared or knocked into the eggs. These spawns usually appear early in Phase Three, and may be delayed effects of the normal whelp generation in Phase Two.

The Onyxia fight is made up of three separate phases. Phase One starts when any character enters her chamber. Phase Two starts when she is brought down to 65% health. At this point she walks to the south end of the room and take flight. Phase Three starts when she is brought down to 40% health. She lands and continues the fight from the ground.

Upon entering Onyxia's Lair, you will fight through a tunnel containing four Onyxian Warders. These are easy raid monsters. The keys to defeating them are to make sure that only the main tank is close enough to them to get hit by their Fire Nova attack, and to pull them carefully, so that you face only one at a time.

When you reach the main chamber at the end of the tunnel, you will see Onyxia resting on the ground. Take this time to buff everyone and ensure that everyone has full health and mana. If you are using Greater Fire Protection Potions, take them now to start the potion cooldown. Select and put on your equipment for an appropriate mix of fire resistance, armor, healing, mana regeneration, and damage output.

Set up a healing rotation on the main tank to ensure he stays at full health, and that healers can regenerate mana between rotations.

Establish two groups (typically group 7 and group 8) as whelp groups. They will kill whelps during phase two. These groups must have at least one mage for AoE and is best to have another form of AoE as well (either a second mage or a warlock). They also require healers and warriors. There should be no whelps in phase one or phase three, but they sometimes happen anyway. These groups should keep an eye out for whelps in those phases but can focus mainly on Onyxia with the rest of the raid.

Establish which groups go where for phase one and phase three. Typically, groups 1, 3, 5, and 7 go left (west), and groups 2, 4, 6, and 8 go right (east).

When everyone is ready, the Main Tank charges in with everyone else following about two or three seconds behind. The main tank runs straight past Onyxia, pulling her to the far north side of the room so that she faces the wall. The best positioning takes a little practice and is a few steps in front of the wall. This is so that the main tank's back is to the wall to limit the effectiveness of her Knock Away ability and so that the main tank is the only one in front of her when she breathes fire.

Everyone else must charge in two or three seconds after the main tank. If they wait longer, there is a danger of attracting attention from a freshly-spawned Onyxian Warder. If they go sooner, they run the risk of getting hit by Onyxia's Flame Breath attack. Don't get ahead of her!

Everyone but the main tank splits to the sides to the northeast and northwest "corners" of Onyxia's chamber. Each side forms three main groups. Closest to Onyxia is the melee group, roughly at her shoulders. Next is the ranged and healing group, which should be right along the wall. Last, and farthest south, is the whelp group.

Initially, nobody attacks Onyxia except the main tank. The main tank is the only one to be fighting Onyxia for at least a minute, or until she drops to 99% health (whichever comes first).

At this point, the DPS characters start doing damage while being careful to avoid drawing aggro away from the main tank. This is not a race. Phase One is a slow, steady fight. Do not try to rush. All DPS characters try for about 50-75% of their max DPS output. Anyone with a way to dump aggro does so (e.g. Hunters can Feign Death, Rogues can Feint) as often as they can. Mages and warlocks use wands to save mana and generate minimal threat (having over 90% mana going into Phase Two is helpful).

Remember that Onyxia's Flame Breath can do up to 4000 damage. Remember this, because if anyone draws aggro away from the main tank, she turns sideways and may breathe. If she does, she can kill all cloth wearers (casters and healers) on that side, very likely causing a wipe. Therefore it is very important to not overdo the damage.

Also remember that Onyxia's Knock Away ability reduces her threat on the main tank. The main tank is unable to hold aggro as well as usual, so the DPS classes must hold back on their damage output.

If, despite this warning, you pull aggro off of the main tank and Onyxia attacks you, attempt to shake her off of you with Feign Death, Vanish, Ice Block, Divine Shield, Divine Protection, or Fade. If that doesn't work, run to the tanking spot at the northern end of the chamber and fight her there. You are going to die anyway, and this will keep Onyxia from breathing flame on other characters as she kills you.

In this phase you must ensure that everyone maintains spacing from each other to reduce blast damage from fireballs. Players need to move around to ensure they have range to Onyxia while she is flying. Ideally you want to be to on either side of the line created by her head-tail axis as her breath always flows through it. This will minimize the distance you need to run to avoid a deep breath should it occur. It's also wise to turn on an aggro warning mod to warn you when you're about to be fireballed. There is always a 2–5 second delay between her targeting someone and actually shooting the fireball. Once targeted, skilled players can distance themselves from teammates to help avoid collateral damage.

When Onyxia takes off, each whelp pit will spawn a large group of whelps that need to be dealt with quickly. The raid should help the whelp groups clear this initial spawning as fast as possible before moving on to help with Onyxia. Since the first spawn is quite large and can kill clothies quite easly, it is advised to put a tank right at the entrance to the whelps pit, who will cast Challenging Shout to aggro the whelps to him. Then the mages can kill those easily. After the initial group is dead the whelps spawn in regular intervals in smaller numbers that can be dealt with fairly easily once you are used to them.

The path of Onyxia's Deep Breath ability is dependent on her position.

During Phase Two, Onyxia has six possible positions in her cave and stays in each position long enough to fire five fireballs. After that, she randomly moves clockwise, counterclockwise or across her chamber. If she chooses to move across her chamber, she will perform a Deep Breath attack on the way. She will emote, "Onyxia takes in a deep breath..." There are a slew of AddOns which announce this across a player's screen.

Upon this announcement, everyone must immediately run to a safe position.

For each of the six possible positions she moves to there are always two positions in which the raid can stand and be safe from the deep breaths. If she's in a corner position, then the two safe positions are the adjacent corners and if she's in a side position then the two safe positions are the adjacent sides. For example if she's in the top-left corner then the top-right and bottom-left corners are both safe and if she's at the top-center then the two safe positions are the left-center and right-center. Anyone not in a safe position usually dies during a deep breath unless they get lucky with resisting the fire damage.

It is useful to have hunters use Track Dragonkin, ping her position on the mini-map, and announce each time she changes position so that everyone can then adjust their position. Ideally, everyone remains fairly close to a safe position at all times during Phase Two.

Get Onyxia down to about 40% health as fast as you can. Ranged damage is the main thing that can hit her while in flight, so it is important to have everyone doing as much ranged DPS as possible. Rogues and other melee can hit her by using special attacks. Track all debuffs and DoTs on her and ensure they are kept up to move through this phase as quickly as possible. Onyxia's targeting does not follow the usual rules during Phase Two, so there is no reason to hold back on damage. The more quickly Phase Two ends the fewer opportunities Onyxia will have to do a Deep Breath.

Phase Two ends as Onyxia is brought to 40% health. At the start of Phase Three, she lands at a random point in her chamber and starts her ground attack. She casts a fear spell within seconds of landing, so all players must position themselves away from the whelp caves before she does so. If not, the fear effect may cause some to run into the whelp eggs, spawning a lot of whelps.

Due to Onyxia's in-flight threat wiping, the main tank will have very little threat as she lands. He must build rage on whelps, then use Sunder Armor and other threat-generating attacks on Onyxia shortly before she lands. Another technique is for the main tank to bandage himself as she is landing due to the large amount of aggro created by the self-healing. Casters stop attacking somewhere between 41% and 44%. Hunters and rogues keep attacking until she starts to land, at which point they Feign Death or Vanish.

In Phase Three everyone should move back to their Phase One positioning with some minor changes. Stand in a spot well away from the cracks that erupt lava. While this will not prevent taking damage, it will limit it somewhat. Make sure everyone is spread out and that the main tank is back to the north end of the room.

There is a considerably better spot for ranged DPS characters. At the exact center of the room is a medium-sized area with fewer lava cracks (prior to Patch 1.11, these did not spew lava at all). Ranged damage-dealers standing here can avoid all damage from Onyxia and the lava, although they may be attacked by whelps. They must stand back far enough to avoid Onyxia's tail. There are two small spikes of rock that make excellent places to stand.

Healers who are healing the main tank should stand against the wall in their corners, as far back as possible. This gives them the best chance to avoid both Onyxia's Fire Breath and Tail Swipe attacks when feared.

Melee must stay well forward of her tail! If you are too far back, she may fear you into her tail, which will toss you into a whelp pit, which will spawn 20 whelps, which will wipe the raid. Also, everyone must stay away from the whelp pits to avoid being feared directly into them. If you do end up spawning a bunch of whelps, call it out so that the whelp groups can kill them quickly. AoE damage is required to have any chance of success.

At beginning of Phase Three, the main tank may have a difficult time re-establishing aggro. Onyxia may attack and kill a half-dozen members of the raid before the main tank finally gets her attention. Getting her attention is a lot faster if, near the end of Phase Two, the main tank applies Sunder Armor and the casters stop attacking. Usually a full 1% health drop (as in Phase One) will ensure complete aggro control for the rest of the fight if people are careful with their DPS.

As in Phase One, if you draw aggro from the main tank, either shake it or run to the tanking spot to die. This is very likely to happen at the beginning of Phase Three to all cloth classes, so be ready for it.

Onyxia's threat at the start of Phase Three is a hot topic of debate. Research in November of 2006 strongly indicates that her Phase Two fireball attack, when it scores a targeted (not AoE) hit, is a complete threat wipe. This would go a long way toward explaining the strange behavior at the start of Phase Three.

Onyxia's fear spell causes a considerable amount of chaos. Aside from disrupting healing and damage-dealing, it causes all characters to lose their positions and to take damage from running through lava spurts. It sometimes causes the main tank to run sideways. When this happens, Onyxia turns to follow him, and may then breathe flame on members of the raid on that side.

The cracks spew lava immediately after the fear effect ends. If your character is standing on a crack when the fear effect ends, move him to a safe spot quickly.

The fear interrupts long-cast spells, and wastes much of the duration of short-term buffs (such as from trinkets). Use these immediately after a fear effect ends, in order to reduce the chance of disruption from the next fear.

It helps to have a Priest be the main healer on the MT during Phase Three. The Priest ability Fear Ward, when cast on the MT during Phase Three, can prevent the main tank from being feared.

Shamans can plant two Tremor Totems next to the tank, three seconds apart. These will usually cause the tank to come out of fear quickly. They need to be renewed during the fight.

Both Alliance and Horde tanks can avoid the fear somewhat via the Stance Dance, as with Magmadar. The shaking screen gives just enough warning to use Berserker Rage. However, the reduced threat generation and extra damage taken from Berserker Stance while the healers are feared can be problematic.

An advanced tactic is to have two tanks, who must both build threat. The Off-Tank hits Berserker Rage to avoid the fear, and becomes the main tank until the fear is over. This requires more skill by the healers and tanks, and more fire resistance gear. However, if done properly, it ensures that Onyxia will never turn due to fear effects. The off-tank may be positioned with the main tank, to avoid repositioning, or at her shoulder, to avoid damage.

If you are not the tank, you must not avoid or break the fear effect. Onyxia will always attack un-feared targets before targets that do have the fear effect. What this means is that if you aren't feared, Onyxia may turn, breathe flame on you and many other players, and wipe the raid. Stay away from tremor totems. Don't use Will of the Forsaken or your PvP trinkets to break fear.

There is a small chance of resisting the fear. If you resist it, Onyxia will attack you. Run to the tanking spot until the main tank recovers from fear and regains aggro.

This part of the fight is similar to Phase One. Keep your DPS under control doing about 50-75% of your max and clearing aggro as often as you can.

Damage-dealing classes can gradually ramp up their damage output as Phase Three progresses and the main tank builds more threat. Hunters can do this more quickly by using Feign Death and Rogues can do so with Vanish. At 10% health, it is usually possible to apply maximum damage. This is a balancing act, as Onyxia must be brought down before attrition from the lava spurts causes the loss of too many players, yet the damage-dealers must not pull aggro from the main tank.

Onyxia is more about long-term patience than all-out DPS and speed. If you follow the strategies laid out here, have patience and practice a little, you should have an easy time beating her. Phase One is very easy if no one pulls aggro off the main tank. Phase Two becomes easy once you figure out how to deal with the whelps, dodge Deep Breath attacks, and keep up ranged DPS and DoTs. Phase Three requires some luck the first several times you do it and a ton of skill on the main tank's part to keep control while being feared and knocked back.

The hardest part of the whole fight is the main tank regaining aggro at the end of Phase Two / beginning of Phase Three. Once that part is mastered, the fight goes a lot more smoothly. Once again, the key is for the main tank to apply Sunder Armor to Onyxia while she is still in the air.

The next-hardest part of the fight is learning to avoid Deep Breath attacks. Once again, the keys here are to keep your character positioned in or near a safe spot at all times during Phase Two and to damage Onyxia so quickly that she has few chances to perform the attack.

Keep your tanks alive at all costs. Since Onyxia is immune to taunt, your main tank cannot regain aggro if he dies and is resurrected. If your main tank does die, your raid's only hope is to have another tank take over.

This is a scripted fight that takes some practice. No matter how accurate any strategy guide is, nothing can prepare you more than experience. Expect a few wipes and plan for it. Some guilds take 20–30 wipes before downing her for the first time, and then continue to have occasional wipes.

Greater Fire Protection Potions are useful during this fight, especially while learning it. They are better than healing potions in dealing with fire damage. Heal with bandages. Healers will be focused on the main tank, so everyone else must be prepared to take care of themselves.

Fire Resistance gear is important for the MT and OT, but is subject to discussion for everyone else. It increases survivability, but people should pay attention not to gimp themselves too much.

Most boss mods provide a large, loud warning before Onyxia performs a Deep Breath attack. They also warn when she enters Phases Two and Three as well as providing general raid usefulness.They are generally recommended for use, as well as usually required by guilds.

The KLH Threat Meter mod provides a fairly accurate estimate of monster threat, although nothing beats being aware of how much threat you are putting up. If everyone uses it, it can help avoid loss of aggro by the main tank.

Onyxia heals herself for 45% over ten seconds. This is extremely rare, but only happens during Phase Three. It appears to happen only in very long fights. Even in long fights, though, it does not usually happen.

The healing is due to a bug, instead of a normal ability. It is not the normal "evade" healing, as Onyxia never evades and can be attacked normally while she heals. It has been reported that she heals when she targets characters on the walls of the cave, but the heal has also been reported when there were no characters on the walls. There may be multiple triggers for this bug.

In a response to a GM ticket posted on the US Staghelm Realm on October 8th 2006, a GM said that after viewing a fight in which Onyxia bug healed, the heal may have been caused by Onyxia being unable to target players who were on the wall causing her to bug out. The GM also stated that this bug is not being considered for correction at this time.

It seems that in phase 2, Onyxia will now sit down and melee attack people. She can then be tanked and melee damaged like if she wasn't flying. As of Patch 2.3, this bug seems to be fixed now which means you can melee her even while in the air, but Onyxia will not sit down and melee attack anymore.

"She has lurked in her lair and done battle with the many brave adventurers who travelled to that familiar location over the years. Now, in honor of the World of Warcraft 5-year anniversary, the dreaded brood mother Onyxia is being revamped to make a return to the forefront of Azeroth, as part of our big plans for the upcoming 3.2.2 content patch. This permanent update to Onyxia will convert the dungeon into 10- and 25-player modes. We will be adding new items to Onyxia’s loot table that have the same model as some of the classic loot from this dungeon, like Tier 2 helms, with stats updated to match the current level of content. There will be a special new item too: a normal drake-sized 310% speed flying mount modeled after Onyxia herself called an Onyxia Broodling. We will also be updating the encounter mechanics to be more fitting for modern raiding, but we can guarantee players will get to experience the frightening horror of deep breaths once again."[1]